1. Field of the Invention
The present invention relates to an engine, and more particularly, relates to an engine configured to be able to prevent muffler mounting bolts to fix a muffler to an engine body, from slackening.
2. Description of the Related Art
Conventionally, as a muffler mounting structure for fixing a muffler to the engine body, a structure in which a muffler is fixed to the engine body with bolts, is generally known.
In a muffler mounting structure disclosed, for example, in Japanese Patent Application Laid-Open No. 2007-2730, fastening parts are fitted into muffler mounting bosses, and they are fixed with a fixing member placed on them to mount the muffler to the engine body.
In the muffler mounting structure of the engine described in the above-mentioned patent document, those muffler mounting bosses are provided nearby an exhaust port.
Accordingly, there is a technical problem that the muffler mounting bosses tend to increase in the temperature, and therefore the fastening parts fitted into the muffler mounting bosses slacken by thermal expansion of the muffler mounting bosses.